Ransomware precursor contained before encryption began
- Affected asset
- FIN-WS12, finance workstation
- Rating
- Extreme Likely 4 × Critical 6 = 24
Description
The EDR platform flagged a process spawning shadow-copy deletion, a common last step before ransomware encrypts. Analysts investigated within minutes, confirmed the behaviour matched a known ransomware playbook, and isolated the host on the agreed authority before any files were encrypted.
Evidence
[edr] 23:41 FIN-WS12: powershell -enc <b64>
-> vssadmin.exe delete shadows /all /quiet
-> parent: winword.exe (macro-enabled attachment)
[analyst] 23:47 behaviour matches ransomware precursor
[action] 23:49 host isolated; no encryption observed
Shadow-copy deletion spawned from a macro-enabled document was caught and the host isolated within eight minutes, before encryption.
Impact
Shadow-copy deletion is one of the last quiet steps before a ransomware attack encrypts and announces itself. Catching it and isolating the host within minutes, out of hours, is the difference between one reimaged workstation and an organisation-wide outage with a ransom demand.
Remediation
Reimage the isolated host and reset the user's credentials. Trace the macro-enabled attachment, block the sender and the pattern, and confirm application control and macro settings would stop a repeat. Hunt across the fleet for the same precursor on other hosts.